Theory of charge transport in diffusive normal metal / unconventional singlet superconductor contacts

Abstract

We analyze the transport properties of contacts between unconventional superconductor and normal diffusive metal in the framework of the extended circuit theory. We obtain a general boundary condition for the Keldysh-Nambu Green's functions at the interface that is valid for arbitrary transparencies of the interface. This allows us to investigate the voltage-dependent conductance (conductance spectrum) of a diffusive normal metal (DN)/ unconventional singlet superconductor junction in both ballistic and diffusive cases. For d-wave superconductor, we calculate conductance spectra numerically for different orientations of the junctions, resistances, Thouless energies in DN, and transparencies of the interface. We demonstrate that conductance spectra exhibit a variety of features including a $V$-shaped gap-like structure, zero bias conductance peak (ZBCP) and zero bias conductance dip (ZBCD). We show that two distinct mechanisms: (i) coherent Andreev reflection (CAR) in DN and (ii) formation of midgap Andreev bound state (MABS) at the interface of d-wave superconductors, are responsible for ZBCP, their relative importance being dependent on the angle $\alpha$ between the interface normal and the crystal axis of d-wave superconductors. For $\alpha =0$, the ZBCP is due to CAR in the junctions of low transparency with small Thouless energies, this is similar to the case of diffusive normal metal / insulator /s-wave superconductor junctions. With increase of $\alpha$ from zero to $\pi /4$, the MABS contribution to ZBCP becomes more prominent and the effect of CAR is gradually suppressed. Such complex spectral features shall be observable in conductance spectra of realistic high-$T_c$ junctions at very low temperature.

References in corpus (57)

• Random-Matrix Theory of Quantum Transport
• Hamiltonian approach to the transport properties of superconducting quantum point contacts
• Tunneling into Current-Carrying Surface States of High T${}_c$ Superconductors
• Quasiclassical Green's function approach to mesoscopic superconductivity
• AC JOSEPHSON EFFECT IN A SINGLE QUANTUM CHANNEL
• Midgap edge states and pairing symmetry of quasi-one-dimensional organic superconductors
• Novel Circuit Theory of Andreev Reflection
• Spin current in ferromagnet/insulator/superconductor junctions
• Local Density of States in a Dirty Normal Metal connected to a Superconductor
• Interference of two electrons entering a superconductor
• Spin-triplet superconductivity in Sr${}_2$RuO${}_4$ probed by Andreev reflection
• Diffusive conductors as Andreev interferometers
• Degenerate ground state in a mesoscopic YBaCuO grain boundary Josephson junction
• Spin polarized tunneling in ferromagnet/unconventional superconductor junctions
• Theory of tunneling spectroscopy in superconducting Sr2RuO4
• Observation of Andreev Surface Bound States in the 3-K phase Region of Sr_2RuO_4
• Circuit theory of unconventional superconductor junctions
• Induced superconductivity distinguishes chaotic from integrable billiards
• Coherent Charge Transport in Metallic Proximity Structures
• Josephson current in s-wave superconductor / Sr_2RuO_4 junctions
• Experimental determination of superconducting parameters for the intermetallic perovskite superconductor ${\text {MgCNi}}_3
• Temperature-dependence of spin-polarized transport in ferromagnet / unconventional superconductor junctions
• Theory of tunneling conductance for normal metal/insulator/triplet superconductor junctions
• Low-Temperature Magnetic Penetration Depth in d-Wave Superconductors: Zero-Energy Bound State and Impurity Effects
• Tunneling conductance of normal metal / $d_{x^2-y^2}$-wave superconductor junctions in the presence of broken time reversal symmetry states near interfaces
• DC Josephson Effect in SNS Junctions of Anisotropic Superconductors
• Scaling Theory of Conduction Through a Normal-Superconductor Microbridge
• Local and macroscopic tunneling spectroscopy of Y(1-x)CaxBa2Cu3O(7-d) films: evidence for a doping dependent is or idxy component in the order parameter
• Spectroscopic evidence for unconventional superconductivity in UBe${}_{13}$
• Disappearance of Ensemble-Averaged Josephson Current in Dirty SNS Junctions of d-wave Superconductors
• Theory of Local Density of States of d-Wave Superconducting State Near the Surfaces of the t-J Model
• Nonlinearity in NS transport: scattering matrix approach
• Theory of Spin polarized Tunneling in Superconducting Sr2RuO4
• Tomography of pairing symmetry from magnetotunneling spectroscopy -- a case study for quasi-1D organic superconductors
• Theory of magnetotunneling spectroscopy in spin triplet p-wave superconductors
• Influences of broken time-reversal symmetry on the d.c. Josephson effects in d-wave superconductors
• Theory of AC Josepson Effect in Superconducting Constrictions
• Broadening of Andreev-Bound States in d_{x^2-y^2} superconductors
• Andreev reflections on Y1-xCaxBa2Cu3O7-delta evidence for an unusual proximity effect
• Theory of charge transport in diffusive normal metal / conventional superconductor point contacts
• Theoretical study of quasiparticle states near the surface of a quasi-one-dimensional organic superconductor $(TMTSF{)}_2{PF}_6$
• Surface electronic scattering in d-wave superconductors
• Mechanisms of Spontaneous Current Generation in an Inhomogeneous d-Wave Superconductor
• Theory of the Josephson effect in superconductor / one-dimensional electron gas / superconductor junction
• Point contact spectroscopy of the electron-doped cuprate superconductor Pr{2-x}Ce{x}CuO4: The dependence of conductance-voltage spectra on cerium doping, barrier strength and magnetic field
• Multiple Andreev reflections and enhanced shot noise in diffusive SNS junctions
• Anomalous proximity effect in d-wave superconductors
• Charge current in ferromagnet-superconductor junction with pairing state of broken time-reversal symmetry
• Boundary conditions for quasiclassical equations in the theory of superconductivity
• Tunneling Spectra of Skutterudite PrOs_4Sb_{12}
• Parity-sensitive measurements based on ferromagnet/superconductor tunneling junctions
• Andreev Bound States, Surfaces and Subdominant Pairing in High Tc Superconductors
• D-Wave Superconductors near Surfaces and Interfaces: A Scattering Matrix Approach within the Quasiclassical Technique
• Suppression and enhancement of the critical current in multiterminal S/N/S mesoscopic structures
• Generalized method of image and the tunneling spectroscopy in high-Tc superconductors
• Tunneling conductance in normal metal - high $T_C$ cuprate junctions in the presence of magnetic field
• Magnetotunneling spectroscopy as a probe for pairing symmetry determination in quasi-2D anisotropic superconductors

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• Symmetry and Topology in Superconductors - Odd-frequency pairing and edge states -
• Topology of Andreev Bound States with Flat Dispersion
• Theory of the proximity effect in junctions with unconventional superconductors
• Odd-frequency superconductivity
• Odd-frequency pairing in normal metal/superconductor junctions
• Anomalous charge transport in mesoscopic triplet superconductor junctions
• Theory of quantum metal to superconductor transitions in highly conducting systems
• Anomalous features of the proximity effect in triplet superconductors
• Theory of enhanced proximity effect by mid gap Andreev resonant state in diffusive normal metal / triplet superconductor junctions
• Theory of Majorana zero modes in unconventional superconductors
• Resonant proximity effect in normal metal / diffusive ferromagnet / superconductor junctions
• Variational Monte Carlo Studies of Pairing Symmetry for the t-J Model on a Triangular Lattice
• Influence of the pair coherence on the charge tunneling through a quantum dot connected to a superconducting lead
• Proximity effect with noncentrosymmetric superconductors
• Proximity effect in clean strong/weak/strong superconducting tri-layers
• Fragile surface zero-energy flat bands in three-dimensional chiral superconductors
• Theory of Josephson effect in unconventional superconducting junctions with diffusive barriers
• Theory of surface Andreev bound states and tunneling spectroscopy in three-dimensional chiral superconductors
• Topological superconductivity and Majorana fermions in hybrid structures involving cuprate high-T_c superconductors
• Spin-sensitive Long-ranged Proximity Effect for Triplet Superconductors
• Odd-frequency pairing and proximity effect in Kitaev chain systems including topological critical point
• Anomalous surface states at interfaces in p-wave superconductors
• Robustness of Spin-Triplet Pairing and Singlet-Triplet Pairing Crossover in Superconductor/Ferromagnet Hybrids
• Proximity effect and its enhancement by ferromagnetism in high-temperature superconductor-ferromagnet structures
• Theory of proximity effect in two-dimensional unconventional superconductor with Rashba spin-orbit interaction
• Influence of magnetic impurities on charge transport in diffusive-normal-metal / superconductor junctions
• Charge and spin transport through a ferromagnet/insulator/unconventional superconductor junction
• Theory of Josephson effect in chiral p-wave superconductor / diffusive normal metal / chiral p-wave superconductor junctions
• Pairing symmetry of superconductivity coexisting with antiferromagnetism
• Quantum point contact conductance in NINS junctions
• Proximity Effect in Normal Metal - High Tc Superconductor Contacts
• Effects of spin orbit coupling in superconducting proximity devices -- application to $\mathrm{CoS}{\mathrm{i}}_2/TiS{\mathrm{i}}_2$ heterostructures
• Nonmonotonic temperature dependence of critical current in diffusive d-wave junctions
• Quantum transport in a normal metal/odd-frequency superconductor junction
• d-wave to s-wave to normal metal transitions in disordered superconductors
• Angular dependence of Josephson currents in unconventional superconducting junctions
• Point-contact spectroscopy in Co-doped CaFe2As2: nodal superconductivity and topological Fermi surface transition
• Theory of thermal and charge transport in diffusive normal metal / superconductor junctions
• Anomalous proximity effect in gold coated (110) $YB{a}_{2}C{u}_3{O}_{7-\delta }$ films: Penetration of the Andreev bound states
• Theory of proximity effect in $s+p$-wave superconductor junctions
• Spin-polarized proximity effect in superconducting junctions
• Non-Abelian Anyons and Non-Abelian Vortices in Topological Superconductors
• Effects of the phase coherence on the local density of states in superconducting proximity structures
• Pairing competition in a quasi-one-dimensional model of organic superconductors (TMTSF)${}_{2}X$ in magnetic field
• Spin and Charge Currents in SNS Josephson Junction with f-wave Pairing Symmetry
• A quantitative model for IcR product in d-wave Josephson junctions
• Proximity effect of time-reversal symmetry broken non-centrosymmetric superconductors
• Does a ferromagnet with spin-dependent masses produce a spin-filtering effect in a ferromagnetic/insulator/superconductor junction?
• Surface State of Inter-orbital Pairing State in Sr${}_2$RuO${}_4$ Superconductor
• Spin conductance in SNN junctions with non-centrosymmetric superconductors
• Electron transport in p-wave superconductor-normal metal junctions
• Magnetoenhancement of superconductivity in composite D-wave superconductors
• Anisotropic differential conductance of a mixed parity superconductor/ferromagnet structure
• Smearing origin of zero-bias conductance peak in Ag-SiO-Bi-2212 planar tunnel junctions: influence of diffusive normal metal verified with the circuit theory
• Quasiparticle spectrum in mesoscopic superconducting junctions with weak magnetization
• Theory of Josephson current on a lattice model of grain boundary in $d$-wave superconductors
• Conductance of d-wave superconductor/normal metal/d-wave superconductor junctions
• Meissner effect in diffusive normal metal / d-wave superconductor junctions